Piston for internal-combustion motors



J. H. BAMBERG.

PISTON FOR !NTERNAL COMBUSTION MOTORS.

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J. H. BAMBERG.

PISTON FOR INTERNAL COMBUSTION MOTORS.

APPLICAHO'N FILED JUNE 28,1916.

lufentnd Mb. 3, 1920.

3 SH EETS-SHEET 2.

4 J H J J. H. BAMBERG.

PISTON FOR INTERNAL COMBUSTION MOTORS.

APPLICATION FILED JUNE 28.1916. 1,329,821 Patented Feb. 3,1920.

3 SHEETS-SHEET 3.

UNITED STATES PATENT OFFICE.

JOSEPH H. BAMBERG, OFTONAWANDA, NEW YORK, ASSIGNOR TO THE ALUMINUMCASTIN GS COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

PISTON FORINTERNAL-COMBUSTION MOTORS.

Specification of Letters Patent.

Patented Feb. 3, 1920.

Application filed June 28, 1916. Serial No. 106,513.

To all whom it may concern Be it known that I, JOSEPH H. BAMBERG, acitizen of the United States, residing at Tonawanda, in the county ofErie and State of New York, have invented certain new and usefulImprovements in and Relating to Pistons for Internal-Combustion Motors,of which the following is a specification.

This invention relates to pistons for use particularly in internalcombustion motors.

One of the objects of my invention is to produce a simple, light,durable and eitlcient skirted piston peculiarly adapted to meet theconditions which exist Within an internal combustion motor cylinder,including the stresses and strains imposed upon the piston, principallyduring the explosion stroke, and by the high heat generated at thistime, which must be (a) efficiently and economically utilized in thetranslation of heat into mechanical energy and (b) that not translatedinto mechanical energy properly dissipated.

My present invention also contemplates an improvement in pistons of thegeneral character disclosed in my- Letters Patent 1,296,589. I g

It further contemplates improvements on the construction of pistondisclosed in Letters Patent of the United States N 0. 1,092,870, toEdward O. Spillman and Louis P. Mooers by simplifying the constructionand manufacture of pistons of this patented type through making them intwo or more parts, if desired of diiferent materials,-and ofconsiderably lightening the construction as compared with the integralcast structure illustrated in the said patent.

Purely for the purposes of disclosure herein I have selected toillustrate and describe one construction of internal combustion motor,skirted piston embodying my improvement.

In the drawings, Figure l is a side elevation of a piston embodying myimprovements.

Fig. 2 is a section on the line 2-2, Fig. 1. Fig. 3 is a section on theline 3 -3, Fig. 2. Fig. 4 is a bottom or lower plan view.

F ig. 5 is a view partly in top or upper plan and partly in section.

1 is the skirt, body or guide portion of the piston, which may be madeof cast iron or a section of steel tubing having diametrically though itwill be understood that if desired it may be machined or treated in anypreferred mechanical manner.

3 indicates the head or top wall and connecting parts of the piston. Itcomprises, preferably, an end wall 3, an annular outer wall 3 preferablysuitably grooved, as in; dicated at 3*, to receive suitable pistonrings, and depending or inwardly turned connecting members 3, 3',connected with the end wall 3 by an annular, inwardly extending .wall orribs 3". The portions 3 and 3 of the piston may be made of an aluminumalloy or any other suitable material. Their principal functions are toassist in translating the heat of'the burning gases in the motorcylinder into mechanical energy, dissipate a part of that heat and tocarry the piston rings in such manner that they will co-act properlywith the inner walls of the cylinderwith which they are adapted tocontact.

The skirt 1 is properly related to and connected with the head 3,preferabl at the lower ends of the connecting mem ers 3, 3 Theseconnecting members may be made in any suitable manner. Preferably I formthe end wall 3, annular flanges or webs 3', 3*, and connecting members3, 3, integrally and of a metallic alloy having relatively low specificgravity, as for example an aluminum alloy, the principal part of which ais composed of the metal aluminum. The head and connecting parts of thep1ston may be cast or otherwise formed 1n any intermediate its endstubular wrist .pin bosses 3, these two bosses being axially alined, inthe well known manner to receive a suitable wrist pin. fine of them mayhave a depending lug or extension 3 formed with a screw-threaded openingto receive a suitsuitable known manner. Preferably each of theconnecting member's 3, 3 carries able locking bolt or screw in a wellknown manner to secure in position the wrist pin to be mounted in thesaid boss.

At its lower end each of the connecting members 3, 3 preferably carriesmeans for axially alining the head end 3 to the guide section 1 andconnecting these parts rigidly together so that they will co-actproperly within the motor cylinder. For the purpose I have illustratedthe lower end of each of the connecting elements 3, 3", respectively, tobe formed with a curvilinear wall 3 carrying outwardly extending pads orspacing lugs 3 and a cylindrical connector or r-ivet like extension 3*.surfaces of the spacing lugs or pads 3 are suitably surfaced to engagethe inner adjacent walls of the guide section 1 so as to space the guidesectionl and the connecting members 3, 3, properly relatively to eachother and to insure the concentricity of the head 3 with the uideportion 1, Near its lower end the guide portion 1 may be formed withdiametrically opposed apertures 1, 1, each of which is preferablycounter-sunk or taper-turned or reamed as indicated, to receive theouter end of the adjacent connector lug 3 which is then upset in thewell known manner within the counter-sunk walls of the adjacent openings1 so as to secure a simple, cheap, durable and positive connectionbetween the body portion 1 of the piston and the connecting members 3,3*, respectively. Each connector member 3, 3, preferably has fourspacing lugs 3 which are arranged about the axis of the adjacentconnecting lug 3 in such manner that the engagement of their outer wallswith the inner adjacent walls of the body section 1 serves to precluderelative movement of the connecting member and body portion 1 about theaxis of the connecting lug 3 The upper end of the body portion 1 of thepiston is separated from the adjacent lower wall of the annular outerwall 3 of the piston head by an air gap M4. The presence of this air gaptends to reduce to a minimum the transfer of heat from the piston headto the upper end of the skirt or guide portion 1 and further provides anavenue of escape inwardly for any excess oil or lubricant which may workits way up to this gap between the head and the skirt. It will be notedthat any lubricant which enters the skirt'either from the air ap 1 orthrough the openings 1, 1", may f ind a ready outlet as the skirt at itsbottom is substantially open, there being substantially nothing on theinside of the skirt to retain lubricant within it.

The disposition of the connecting members 3, 3, and web 3* relative tothe top or end wall 3 is such as materially to The outer strengthen andsupport the top or end wall 3' near its center and where it-is subjectedto the greatest stresses at thetime of the explosion within the motorcylinder. In fact, my improved piston is extremely rigid, rugged anddurable. The head and connecting element 3 may be suitably ribbed orWebbed between the inner, surface of the end wall 3 .and the adjacentwrist pin bosses, as indicated by the webs 3, ifdesired. b

It will be understood that the sleeve or skirt 1 may be constructed soas snugly to fit the inner walls of the motor cylinder, whereas the head3 may be given. a considerable amount of clearance between itsperipheral wall 3 and theinner wall of the cylinder, to allow for allnecessary expansion of the head due to-the high temperatures to which itis subjected. The heat transmitted to the head which is not translatedinto mechanical energy is transferred downwardly by the connectingmembers 3, 3, to the lower end of the skirt, and much of it is given upto the surrounding air or vapor and thus dissipated so that the skirt iskept relatively cool and may be readily lubricated to provide andmaintain the proper working relationship between it and theinner wall ofthe motor cylinder. The fit between the skirt and the inner wall of thecylinder, as before indicated, may be a snug sliding fit, and the areaof the skirt which co-aets with the inner wall of the motor cylinder issuch as to, insure against slapping or rapping of the piston against theinner wall of the cylinder. In fact the objectionable so-called pistonslap, incident to the operation of numerous types of pis tons for useininternal combustion motors, is eliminated by the use of a pistonconstructed in accordance with my invention.

Furthermore, a piston embodying my improvements herein describedpractically eliminates so-called oil-pumping or transfer of an undueamount of oil or lubricant from the crank case to the upper end of thepiston, resulting in undesirable smoking and undue and troublesomecarbonization, amon other things.

Owing to the fact-that the. sleex e or skirt is maintained relativelycool under all normal working conditions, the possibilities of scoringthe inner walls of the cylinder are practically eliminated.

Owing to the presence of the air gap or air space 4 betweenthe upperedge of the skirt or body section 1 and thelower edge of the annularportion 3 of the piston head, the heat from the piston head Will betransmitted inwardly and downwardly so that suchportion of it as doesreach the skirt or body by conduction will do so at the lower end of theskirt and. will not be sufiicient in amount tocause the necessary expansion of the skirt to effect binding between the skirt and inner wallsof the cylinder or scoring.

It will be noted that my composite piston may be made relatively lightin weight, which is of material advantage in assisting in reducing theweight of the reciprocating parts of the motor.

Pistons of my improved construction Will be found to operatecomparatively noiselessly, smoothly and efiiciently.

To those skilled in the art many modifications of and widely differingembodiments and applications ofmy "invention will suggest themselves,without departing from the spirit and scope thereof. My disclosures andthe descriptions herein are purely illustrative and are not intended tobe in any sense limiting.

What I claim is:

1. A piston for an internal combustion motor-comprising a guide sectionseparately formed and a head and connector section formed integrally andcomprising an end wall having an outer annular flange and a pair ofinwardly extending connector members each formed intermediate its endswith a wrist pin boss and adjacent its lower end with a plurality ofoutwardly extending projections, one of which is rigidly secured to theguide section near its lower end and another of which engages the innerwall of said guide section to insure axial alinement of said vsections.

2. A piston for an internal combustion motor comprising a guide sectionand a head and connector section, which are formed separately, said headand connector section being a casting and comprising an end wall havingan outer flange anda pair of inwardly extending connector members eachformed intermediate its ends with'a wrist pin boss and adjacent itslower .end with a plurality of outwardly extending projections, one ofwhich is rigidly secured to said guide section near its lower end andanother of which is surfaced concentrically to said head and engages theinner wall of said guide section to position said sectionsconcentrically.

3. A piston for an internal combustion motor comprising a guide sectionand a head and connector section, said guide section being formed nearits lower end with a pair of alined openings extending through the wallsthereof, and said connector being formed with a pair of axially alinedoppositely extending connector-lugs each arranged to enter the adjacentone of said openings through said guide section and to have its .outerend upset against the walls of said opening.

4. A piston for an internal combustion motor comprising a guide sectionand a head and connector section, said guide section being formed nearits lower end with a pair of alined openings extending through the wallsthereof, and said connector being formed with (1) a pair of axiallyalined oppositely extending connector lugs each arranged to enter theadjacent one of said openings through said guide section and to besecured to said guide section and (,2) spacing lugs to position saidsections concentrically.

5. A piston for an internal combustion motor comprising a guide sectionand a head and connector section, and said connector cally and (2)separate means for securing said sections together.

6. A composite piston comprising a tubular iron guide section havingrelatively thin walls, a combined piston head and con nector elementcast of a metallic alloy having a lower specific gravity than iron andcomprising an end wall having an annular flange, the bottom of which isspaced from the upper end of said guideby an air gap, and a pair ofinwardlyextending connecting members, each having intermediate its endsa Wrist 'pin boss which is axially alined with the wrist pin boss of theother and adjacent its lower end a plurality of spacing lugs disposed toengage the inner walls of said guide section adjacent the lower endthereof, and means for securing the lower end of each of said connectingmembers to the adjacent wall of said guide sections. 7. A compositepiston comprisin a tubular iron guide section having re atively thinwalls, a combined piston head and connector element cast of ametallicalloy having a lower specific gravity than iron and comprising an endwall having an annular flange, the bottom of which is spaced from theupper end of said skirt by an air gap, and a pair of inwardly extendingconnecting members, each havin intermediate its ends a wrist pin boss wich is axially alined with the wrist pin boss of the other and adjacentits lower end a plurality of spacirig lugs disposed to engage the innerwalls 0 said guide section adjacent the lower end thereof, and means forsecuring the memfrom said end wall intermediate the centerthereof andsaid annular flange, and each connector member having intermediate itsends a wrist pin boss axially alined with the wrist pin boss of theother and near its lower end spacing means having spacing surfacesconcentric with the axis of said head, a relatively thin walled tubularguide section having its upper end spaced from the lower end of saidannular flange of the piston head to provide an air gap therebetween,the spacing surfaces of said connectin members contacting with saidguide section on its inner wall and near the lower end thereof, andmeans for securing said connecting members near their lower ends to theadjacent walls of said guide section.

9. A piston comprising a head and connector portion integrally formed ofmetallic alloy having relatively low specific gravity, and comprising atop wall having an annular flange at its periphery and a pair ofconnecting members extending downwardly from said end wall intermediateits center and said'annular flange and each carrying intermediate itsends a wrist pin boss alined with the wrist pin boss of the other, andhaving at its lower end an outwardly extending connecting lug, and atubular relatively thin walled guide section disposed to have an airgap. between its upper end wall and the lower end wall of said annularsection, and being formed adjacent its lower end with openings each toreceive one of said connecting lugs on an ad acent connecting member andbe connected by said lug to said connecting member.

10. A piston comprising a head and connector portion integrally formedof metallic alloy having relatively low specific gravity, and comprisinga top wall having an annuwall and the lower end wall of said annularsection, and being formed adjacent its lower end with openings each toreceive one of said connecting lugs on an adjacent connectingmember andbe connected by said lug to said connecting member, the walls of saidopenings in said guide section being tapered and the outer ends of saidconnecting lugs being upset against said tapered walls.

11. A piston for an internal combustion motor comprising a guide sectionseparately formed and a head and connector section formed integrally andcomprising an end wall having an outer annular flange and a pair ofinwardly extending connecting memers each formed intermediate its endswith a wrist pin boss and adjacent its lower end with a plurality ofspacing lugs disposed to engage the inner wall of said guide sectionadjacent the lower end thereof, and

means for securing the lower end of each of said connecting members tothe adjacent wall of said guide section between the points at which saidspacing lugs engage the inner wall of said guide section.

In testimony whereof I aflix my signature.

' JOSEPH H. BAMBERG.

